CN115000816A

CN115000816A - Spark plug

Info

Publication number: CN115000816A
Application number: CN202210743470.1A
Authority: CN
Inventors: 许威; 邢政; 潘畅
Original assignee: Chery Automobile Co Ltd
Current assignee: Chery Automobile Co Ltd
Priority date: 2022-06-27
Filing date: 2022-06-27
Publication date: 2022-09-02

Abstract

The application relates to a spark plug, and belongs to the technical field of automobile engines. The spark plug comprises a fixing piece, a ceramic body, a center electrode, a resistance sealing material, a wiring rod and a side electrode; the fixing piece comprises an outer fixing piece and an inner fixing piece, the outer fixing piece is rotatably connected with the inner fixing piece, the outer fixing piece is provided with external threads and is used for being connected with an engine cylinder cover, a first limiting bulge is arranged on the outer side wall of the inner fixing piece, and the first end face of the first limiting bulge is in contact with the outer fixing piece; the wire connecting rod comprises a rod body and a rotary limiting chuck, the rod body is connected with the ceramic body, and a clamping groove is formed in one end, far away from the ceramic body, of the rotary limiting chuck; the side electrode is connected with the inner fixing piece. By means of the method and the device, when the spark plug is installed in an engine cylinder cover, the orientation of the side electrode can be determined, so that the probability that the cylinder successfully ignites when gas in the cylinder is thin can be improved, and oil consumption of an automobile during starting is further reduced.

Description

Spark plug

Technical Field

The application relates to the technical field of automobile engines, in particular to a spark plug.

Background

Nowadays, in order to meet the requirements of energy conservation and emission reduction, more and more automobiles emphasize that the ignition of an automobile engine is completed under the working condition that the concentration of mixed gas in a cylinder is relatively thin so as to reduce the oil consumption of the automobile when the automobile is started. When the gas mixture in the cylinder is lean, the orientation of the spark plug-side electrode is important for successful ignition of the engine.

Currently, spark plugs are typically mounted to the engine cylinder head by a threaded connection, with the side electrode being in rotation at all times during the mounting process. Because the spark plug thread start location and the engine cylinder head thread start location are random, the orientation of the side electrode at the end of installation is also random and the side electrode may be in a relatively poor orientation at the end of installation. For example, the side of the side electrode away from the center electrode is directed toward the oil passage outlet, which may result in a decrease in the success rate of ignition of the automobile engine.

Disclosure of Invention

The embodiment of the application provides a spark plug, which can solve the technical problems existing in the related technology, and the technical scheme of the spark plug is as follows:

a spark plug is provided, which includes a fixing member, a ceramic body, a center electrode, a resistance seal, a terminal rod, and side electrodes;

the fixing piece comprises an outer fixing piece and an inner fixing piece, the outer fixing piece is of a tubular structure and is provided with an external thread, the external thread is used for being connected with an engine cylinder cover, the inner fixing piece is of a tubular structure, a first limiting protrusion is arranged on the outer side wall of the inner fixing piece, the part, between the first end of the inner fixing piece and the first limiting protrusion, of the inner fixing piece is located in the outer fixing piece and is in rotary connection with the outer fixing piece, the part, between the second end of the inner fixing piece and the first limiting protrusion, of the inner fixing piece is located outside the outer fixing piece, the first limiting protrusion is provided with a first end face, a second end face and a first side face, the first end face is in contact with the outer fixing piece, the second end face is used for being in contact with the engine cylinder cover, and the diameter of the first side face is smaller than the small diameter of the external thread;

the ceramic body is of a tubular structure, is positioned in the inner fixing piece and is connected with the inner fixing piece;

the central electrode is positioned in the ceramic body, one end of the central electrode extends out of one end of the ceramic body and the second end of the inner fixing piece, and the central electrode is connected with the ceramic body;

the resistor sealing material is positioned in the ceramic body and connected with the ceramic body, and one end of the resistor sealing material is connected with the other end of the central electrode;

the wiring rod comprises a rod body and a rotary limiting chuck, the rod body is positioned in the ceramic body and connected with the ceramic body, and one end of the rod body is connected with the other end of the resistance sealing material; the rotary limiting chuck is positioned at the other end of the ceramic body and is connected with the ceramic body and the rod body, a clamping groove is formed in one end, far away from the ceramic body, of the rotary limiting chuck, and the clamping groove is used for being clamped with a fixing tool so as to prevent components, except the outer fixing piece, in the spark plug from rotating relative to the outer fixing piece;

the side electrode is located at the second end of the inner fixing piece and connected with the inner fixing piece.

In a possible implementation manner, a first end face of the first limiting protrusion is a circular ring surface and is perpendicular to the outer side wall of the inner fixing piece, a second end face of the first limiting protrusion is a conical surface, and the radius of the conical surface close to the first end face is larger than the radius of the conical surface far away from the first end face.

In one possible implementation, the spark plug further includes a stop washer located at and connected to the second end face.

In a possible realization, the stop washer is made of an elastic non-slip material.

In a possible implementation manner, the outer side wall of the inner fixing piece is further provided with a second limiting protrusion, and the second limiting protrusion is located between the first limiting protrusion and the first end of the inner fixing piece;

the inner wall of the outer fixing piece is provided with a third limiting protrusion, the third limiting protrusion is located between the first limiting protrusion and the second limiting protrusion, and the inner diameter of the third limiting protrusion is smaller than the outer diameter of the second limiting protrusion.

In a possible implementation manner, one end of the outer fixing piece, which is far away from the first limiting protrusion, is provided with a bolt cap structure.

In one possible embodiment, the rotation limiting chuck has a solid or hollow structure.

In one possible implementation manner, the clamping groove (52A) of the rotation limiting clamping head (52) is a through type groove.

In one possible embodiment, the through-opening direction of the slot and the orientation of the lateral electrode are identical.

In one possible embodiment, the inner fastening element is connected to the ceramic body in a sealing manner.

The technical scheme provided by the embodiment of the application at least comprises the following beneficial effects:

in an embodiment of the present application, a spark plug includes a fixing member, a ceramic body, a terminal rod, and a side electrode. The fixing piece comprises an outer fixing piece and an inner fixing piece, the outer fixing piece is rotatably connected with the inner fixing piece, the outer fixing piece is provided with external threads and can be in threaded connection with the engine cylinder cover, a first limiting protrusion is arranged on the outer side wall of the inner fixing piece, and the first end face of the first limiting protrusion is in contact with the outer fixing piece. The rotation limiting chuck of the junction pole is provided with a clamping groove. The side electrodes are connected to the inner fixing member, and the junction rod and the inner fixing member are connected to the ceramic body. The rotation limiting chuck can rotate synchronously with the side electrode. Like this, when the installation spark plug, can get up the draw-in groove joint of fixing tool and spacing dop, when keeping fixing tool to be in irrotational state, rotatory outer mounting is fixed with outer mounting and engine cylinder head. The fixed of holding fixing tool can keep rotatory spacing dop irrotational to guarantee that the orientation of side electrode does not take place rotatoryly, can be towards the direction that is favorable to the engine to strike sparks most, improve the engine success rate of striking sparks.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of a spark plug according to an embodiment of the present application;

FIG. 2 is a schematic structural view of an inner fixing member of a spark plug according to an embodiment of the present invention;

FIG. 3 is a schematic view of a stop washer of a spark plug according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural view of a fixing member of a spark plug according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a fixing member of a spark plug according to an embodiment of the present invention;

FIG. 6 is a schematic view of a rotation limiting chuck for a spark plug according to an embodiment of the present disclosure;

fig. 7 is a schematic structural view of a spark plug according to an embodiment of the present invention.

Description of the figures

1. A fixing member; 2. a ceramic body; 3. a center electrode; 4. a resistor sealing material; 5. a wire connecting rod; 6. a side electrode; 7. a stop washer; 8. a rod spring of the ignition coil;

11. an outer fixing member; 12. an inner fixing member; 31. a first portion of the center electrode; 32. a second portion of the center electrode; 51. a rod body; 52. rotating the limiting chuck;

111. an external thread; 112. a third limiting bulge; 113. a bolt cap structure; 121. a first limit protrusion; 122. a first end of the inner fixture; 123. a second end of the inner fixing member; 124. a second limit bulge;

121A and a first end surface of the first limiting protrusion; 121B, a second end surface of the first limiting protrusion; 121C, a first side surface of a first limit protrusion; 52A, a card slot.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The present embodiment provides a spark plug, as shown in fig. 1, which includes a fixing member 1, a ceramic body 2, a center electrode 3, a resistance seal 4, a terminal rod 5, and a side electrode 6. The fixing member 1 may include an outer fixing member 11 and an inner fixing member 12, and the terminal rod 5 may include a rod body 51 and a rotation limiting chuck 52.

In one example, the terminal rod 5 may be connected to a rod spring 8 of the ignition coil, and the resistance seal 4 may be connected at one end to the terminal rod 5 and at the other end to the center electrode 3, the center electrode 3 being adjacent to the side electrode 6.

In the following, the respective parts of the spark plug will be described:

a fixing part 1

The mount 1 is a member that fixes the entire spark plug to the cylinder head of the engine.

As shown in fig. 1, the fixing member 1 includes an outer fixing member 11 and an inner fixing member 12, and the outer fixing member 11 is rotatably connected to the inner fixing member 12.

The outer fixing member 11 has a tubular structure and has an external thread 111, the external thread 111 being for attachment to the engine cylinder head. The outer fixing member 11 may have a circular through hole, an axis of the circular through hole coincides with an axis of the outer fixing member 11, the outer fixing member 11 may include a cylindrical inner sidewall and two end surfaces, wherein a diameter of the inner sidewall of the outer fixing member 11 may be D1, and the inner sidewall of the outer fixing member 11 and the outer sidewall of the inner fixing member 12 may be adjacent to each other with a certain gap. An end surface located at the middle of the inner fixing member 12, which may be perpendicular to the inner sidewall of the outer fixing member 11, is used to contact the inner fixing member 12.

The external thread 111 may be a fine thread and the profile may be an equilateral triangle with large fillets at the roots.

Therefore, stress concentration at the root of the tooth can be reduced, and because the spark plug is positioned in the cylinder cover of the engine, the engine needs to be ignited frequently, mixed gas in the cylinder has a load effect on the spark plug, and the external thread 111 is set to be a fine thread, so that the external fixing piece 11 can have good self-locking performance under the load effect, and the connection between the external fixing piece 11 and the cylinder cover of the engine is prevented from shaking.

The inner fixing member 12 also has a tubular structure, and the inner fixing member 12 may have a circular through-hole whose axis coincides with the axis of the outer fixing member 11. The inner fastener 12 includes an outer sidewall, an inner sidewall, a first end 122 and a second end 123, the outer sidewall of the inner fastener 12 may have a diameter D2, and D2 is less than D1. The outer side wall of the inner fixing member 12 is provided with a first limiting protrusion 121, the first limiting protrusion 121 comprises a first end surface 121A, a second end surface 121B and a first side surface 121C, wherein the first end surface 121A is used for contacting with the outer fixing member 11, the second end surface 121B is used for contacting with the engine cylinder head, and the diameter of the first side surface 121C is smaller than the small diameter of the external thread 111 and larger than the diameter D1 of the inner side wall of the outer fixing member 11. The first stopper protrusion 121 divides the inner fixing member 12 into two parts. The region between the first end 122 of the inner fixing member 12 and the first stopper protrusion 121 is a first portion of the inner fixing member 12, the region between the first stopper protrusion 121 and the first end 122 of the inner fixing member 12 is a second portion of the inner fixing member 12, the first portion of the inner fixing member 12 is located in the outer fixing member 11, and the second portion of the inner fixing member 12 is located outside the outer fixing member 11.

With the above structure, the inner fixing member 12 is inserted through the threaded hole of the engine cylinder head, the second end face 121B of the first stopper protrusion 121 of the inner fixing member 12 is brought into contact with the engine cylinder head, and the outer fixing member 11 is placed at the threaded hole of the engine cylinder head. Then, by rotating the outer mount 11 around the axis of the outer mount 11, the outer mount 11 is gradually screwed into the engine cylinder head due to the external thread 111, and when the outer mount 11 contacts the first end face 121A, a force is applied to the inner mount 12 to fix the inner mount 12 between the engine cylinder head and the outer mount 11. In addition, since the inner side wall of the outer fixing member 11 and the outer side wall of the inner fixing member 12 may be adjacent to each other with a certain gap therebetween, the outer fixing member 11 is not subjected to a frictional force from the inner fixing member 12 during rotation of the outer fixing member 11, and the rotational resistance of the outer fixing member 11 is small, thereby improving the mounting efficiency of the spark plug.

Secondly, the ceramic body 2

The ceramic body 2 is a member for fixing and protecting the center electrode 3, the resistance seal 4 and the terminal rod 5 in the entire spark plug.

As shown in fig. 1, the ceramic body 2 may have a tubular structure. The ceramic body 2 wraps the central electrode 3, the resistance sealing material 4 and the wiring rod 5 and is connected with the central electrode 3, the resistance sealing material 4 and the wiring rod 5. The ceramic body 2 is located in the inner fixing member 12 and is connected to the inner fixing member 12.

Alternatively, the ceramic body 2 may be entirely located in the inner fixing member 12, or may be partially located in the inner fixing member 12. When the ceramic body 2 is completely positioned in the inner fixing member 12, the contact area between the ceramic body 2 and the inner fixing member 12 is large, and the connection therebetween is firm.

The ceramic body 2 and the part of the central electrode 3, the resistance sealing material 4 and the part of the terminal rod 5, and the ceramic body 2 and the inner fixing member 12 may be connected by a fixed connection, for example, a riveting or an interference fit.

Alternatively, the axial position of the inner fixing member 12 may have a rectangular through hole, the inside of which is the ceramic body 2, accordingly, the portion of the ceramic body 2 located in the inner fixing member 12 may have a cubic structure, and the portion of the ceramic body 2 fills the rectangular through hole of the inner fixing member 12. The rectangular through hole may have four rectangular inner side walls opposite to each other in pairs, and the length of the side of the four inner side walls, which is located on the same plane as the first end 122, is greater than the rod diameter of the rod body 51.

Thus, the relative rotation between the inner fixing member 12 and the ceramic body 2 can be prevented without performing a fixed connection between the portion of the ceramic body 2 located in the inner fixing member 12 and the inner fixing member 12.

The material of ceramic body 2 may be any of various materials having excellent electrical insulation, mechanical strength, and heat resistance, such as boron nitride ceramics and aluminum nitride ceramics. The material of the ceramic body 2 is not limited to the embodiment.

From the installation process of the spark plug, because the ceramic body 2 has good mechanical strength, the ceramic body 2 tightly wraps part of the center electrode 3, the resistance sealing material 4 and part of the wiring rod 5, so that the center electrode 3, the resistance sealing material 4 and the wiring rod 5 can be protected in the installation process of the spark plug, and the center electrode 3, the resistance sealing material 4 and the wiring rod 5 are prevented from being deformed in a twisting mode.

In the use process of the spark plug, the ceramic body 2 has better electrical insulation and heat resistance, so that an insulation and heat insulation barrier can be effectively established between the spark plug and an engine cylinder, the current generated by an ignition coil is prevented from being directly communicated with the engine cylinder to cause short circuit, ignition failure is avoided, and the phenomenon that the spark plug cannot be taken down from an engine cylinder cover due to the fact that the fixing piece 1 is deformed by heating is avoided.

Three, a central electrode 3 and a side electrode 6

The center electrode 3 and the side electrode 6 are components for ignition in the spark plug. As shown in fig. 1 and 7, the center electrode 3 has a columnar structure, and the side electrodes 6 have a bent plate-like structure.

The center electrode 3 may comprise two parts, a first part 31 of the center electrode 3 being connected to the ceramic body 2 and the resistive seal 4, and a second part 32 of the center electrode 3 being located at an end of the first part 31 remote from the ceramic body 2 and being connected to the first part 31. The first portion 31 and the second portion 32 of the center electrode 3 may each have a columnar structure, and the first portion 31 may have a diameter larger than that of the second portion 32, and the first portion 31 and the second portion of the center electrode 3 may be integrally formed.

The bending direction of the side electrodes 6 is the direction of the electrical measurement, and the side electrodes are generally oriented toward the center electrode 3. The thickness of the side electrode 6 may be equal to the thickness of the second end 123 of the inner fixing member 12 and slightly smaller than the diameter of the first portion 31 of the center electrode 3, and the width of the side electrode 6 may be equal to the diameter of the first portion 31 of the center electrode 3. One end of the side electrode 6 is welded to the second end 123 of the inner fixing member 12 and the other end is located on an extension of the axis of the second portion 32 of the center electrode 3. The second portion 32 of the central electrode 3 is adjacent to the side electrode 6, and a gap exists between the central electrode 3 and the side electrode 6, and the size of the gap may be equal to the length of the second portion 32.

As shown in fig. 1, the center electrode 3 is partially located in the ceramic body 2. One end of the center electrode 3 is positioned in the ceramic body 2 and connected to the resistive sealing material 4, and the other end of the center electrode 3 extends out of one end of the ceramic body 2 and the second end 123 of the inner fixing member 12. The side electrode 6 is located at the second end 123 of the inner fixing 12 and is connected to the inner fixing 12.

Thus, after the ignition coil generates the current, the current reaches the center electrode 3 via the terminal rod 5 and the seal resistor 4, and since the diameter of the second portion 32 is smaller than that of the first portion in the center electrode 3, the second portion 32 corresponds to a pointed structure compared to the first portion 31. When the current generated by the ignition coil is transmitted to the central electrode 3, due to the point discharge effect, more charges are collected at the end of the second part 32 far away from the first part 31, and under the action of the charges, the current breaks down the mixed gas between the second part 32 and the side electrode 6 to generate electric sparks, so that the mixed gas in the cylinder of the automobile engine is ignited, and the ignition starting of the automobile engine is completed.

The material of the center electrode 3 and the side electrode 6 may be various materials having good conductivity and burning resistance, for example, nickel-copper alloy, iridium-platinum alloy, or the like. Meanwhile, the material of the central electrode 3 and the material of the side electrode 6 may be the same or different, so that a technician may set the material of the central electrode 3 and the material of the side electrode 6 according to actual needs, and the embodiment is not limited to the material of the central electrode 3 and the material of the side electrode 6.

Fourth, resistance sealing material 4

The resistance seal 4 is a component of the spark plug for transmitting current and limiting the magnitude of the current.

As shown in fig. 1, the resistive seal 4 is disposed in the ceramic body 2, and one end of the resistive seal 4 is connected to the rod 51 and the other end is connected to the center electrode 3. The resistive seal 4 is a cylindrical structure that may have a diameter equal to the diameter of the first portion 31 of the center electrode 3.

The resistor seal 4 may be a current limiting resistor wrapped in a conductive material. On one hand, the presence of the resistive sealing material 4 can facilitate the electrical connection between the terminal rod 5 and the center electrode 3; on the other hand, the resistance sealing material 4 can increase the resistance between the ignition coil and the central electrode 3, so that the current between the ignition coil and the central electrode 3 is controlled within a reasonable range, and the ignition coil is prevented from generating excessive current to damage the ignition coil and the spark plug.

Fifth, the junction pole 5

The terminal rod 5 is a component for transmitting current during use of the spark plug and also for limiting during installation of the spark plug.

The material of the terminal rod 5 may be various materials having good conductivity and burning resistance, such as nickel-copper alloy, iridium-platinum alloy, and the like. Meanwhile, the material of the terminal rod 5 is not limited in this embodiment.

In one example, as shown in fig. 1, the terminal rod 5 may be connected to a rod spring 8 of the ignition coil from the viewpoint of use of the spark plug.

In this way, the ignition coil can convert the low-voltage electric energy of the automobile into the high-voltage electric energy and send a discharge command at an accurate ignition timing after receiving and executing a Control signal sent by an Electronic Control Unit (ECU). After the ignition coil generates current, the current can sequentially pass through the connecting rod 5 and the resistance sealing material 4 through the connecting rod spring 8 of the ignition coil and then reach the central electrode 3, and then the current breaks through mixed gas between the central electrode 3 and the side electrode 6, so that electric sparks are generated, the mixed gas in a cylinder of the automobile engine is ignited, and the ignition starting of the automobile engine is completed.

From the viewpoint of the mounting process of the spark plug, as shown in fig. 1, the terminal rod 5 may include a rod body 51 and a rotation-limiting collet 52, the rod body 51 being located in the ceramic body 2 and connected to the ceramic body 2. One end of the rod body 51 is connected with one end of the resistance sealing material 4, and the other end of the rod body 51 is connected with the rotation limiting chuck 52. The rotation limiting chuck 52 extends out of the ceramic body 2 and is connected with the ceramic body 2 and the rod body 51. The rotation limiting chuck 52 has a catching groove 52A at an end away from the ceramic body 2.

Thus, when installing the spark plug, the technician may first engage the fastening tool in the engagement slot 52A to limit rotation of the terminal rod 5 during installation of the spark plug. Then, the inner mount 12 is passed through the threaded hole of the engine cylinder head, the second end face 121B of the first stopper projection 121 of the inner mount 12 is brought into contact with the engine cylinder head, and the outer mount 11 is placed outside the threaded hole of the engine cylinder head. Next, the external fixing member 11 is rotated, the external thread 111 is screwed into the threaded hole of the engine cylinder head, and when the external fixing member 11 comes into contact with the first end face 121A of the first stopper protrusion 121, the rotation of the external fixing member 11 is stopped, and at this time, the first stopper protrusion 121 is clamped by the external fixing member 11 and the engine cylinder head, and the spark plug is firmly mounted in the engine cylinder head. In this process, since the ceramic body 2 is fixedly connected to the terminal rod 5, the inner fixing member 12 is also fixedly connected to the ceramic body 2, and the side electrode 6 is fixedly connected to the second end 123 of the inner fixing member 12. Therefore, when the terminal rod 5 is not rotated, the side electrode 6 is not rotated. Therefore, the orientation of the side electrode can be determined when the spark plug is mounted, as long as the rotation of the engaging groove 52A is prevented during the process of the spark plug.

Some optional features of the spark plug are described in detail below:

the first structural feature is that the first end surface 121A of the first limiting protrusion 121 may be a circular ring surface and perpendicular to the outer side wall of the inner fixing member 12, the second end surface 121B of the first limiting protrusion 121 may be a conical surface, and the radius of the conical surface near the first end surface 121A is greater than the radius of the conical surface far away from the first end surface 121A.

As shown in fig. 2, the first end surface 121A of the first position-limiting protrusion 121 is a circular surface perpendicular to the outer side wall of the inner fixing member 12, the second end surface 121B of the first position-limiting protrusion 121 is a conical surface, and the radius of the conical surface near the first end 122 is larger than the radius of the conical surface near the second end 123. The edge of the first end surface 121A and the edge of the second end surface 121B with a larger radius are connected to the first side surface 121C, and the diameter of the first end surface 121A is equal to the diameter of the edge of the second end surface 121B with a larger radius.

Thus, since the first end surface 121A is perpendicular to the outer side wall of the inner fixing member 12, the outer fixing member 11 can be more stable when contacting the first end surface 121A. Meanwhile, because the outer fixing member 11 will provide an acting force to the first limiting protrusion 121 when contacting the first limiting protrusion 121, and the second end surface 121B is a conical surface, and the radius of the conical surface near the first end 122 is greater than the radius of the conical surface near the second end 123, the structure of the second end surface 121B can increase the strength of the first limiting protrusion 121, so as to ensure that the first limiting protrusion 121 is not deformed under the action of the acting force.

In an implementation, a surface of the engine cylinder head, which is used for contacting with the second end surface 121B, may be provided as a conical hole, and the conical angle of the conical hole is the same as that of the second end surface 121B. In this way, when the inner fixing member 12 is inserted through the threaded hole of the engine cylinder head, the conical hole in the engine cylinder head can serve to guide the second end face 121B, facilitating contact of the second end face 121B with the engine cylinder head.

Optionally, the spark plug may further include a stop washer 7, the stop washer 7 being located on the second end face 121B and connected to the second end face 121B. The stop washer 7 may be made of a resilient non-slip material.

As shown in fig. 3, the stopper washer 7 is a conical thin plate having a through hole, and the stopper washer 7 is located on the second end surface 121B and connected to the first end surface 121B.

Thus, the friction between the second end surface 121B and the engine cylinder head can be increased, so that the torsional stress generated when the wire connecting rod 5 is limited to rotate is dispersed to other components, and the possibility of deformation of the spark plug due to the torsional stress during the installation process is reduced. During the process of installing the spark plug, friction may occur between the outer fixing member 11 and the inner fixing member 12, and at this time, if only the fixing tool is clamped in the clamping groove 52A, the rod 51 is in a fixed state at the end where only the clamping groove 52A is located, and the clamping groove 52A bears a large torsional stress. After the stop washer 7 is arranged on the second end face 121B, the friction force between the second end face 121B and the engine cylinder head can be increased, which is equivalent to that the other end of the rod body 51 is also in a fixed state, so that the torsional stress borne by the clamping groove 52A is reduced, and the clamping groove 52A is prevented from being deformed or even damaged due to the fact that the torsional stress is concentrated on the clamping groove 52A.

The structure is characterized in that the outer side wall of the inner fixing member 12 can also be provided with a second limit protrusion 124, and the inner wall of the outer fixing member 11 can be provided with a third limit protrusion 112.

As shown in fig. 4, the outer side wall of the inner fixing member 12 has a second limit protrusion 124, the inner wall of the outer fixing member 11 has a third limit protrusion 112, both the second limit protrusion 124 and the third limit protrusion 112 are annular protrusions, and the inner diameter of the third limit protrusion 112 is smaller than the outer diameter of the second limit protrusion 124. The second position-defining projection 124 is located between the first position-defining projection 121 and the first end 122 of the inner fixing member 12, and the third position-defining projection 112 is located between the first position-defining projection 121 and the second position-defining projection 124. The second position-limiting protrusion 124 and the third position-limiting protrusion 112 are both annular protrusions, and the protrusion heights of the second position-limiting protrusion 124 and the third position-limiting protrusion 112 may be the same and are both (D1-D2)/2.

Thus, the outer fixing member 11 can be prevented from falling off from the first end 122 of the inner fixing member 12, and the outer edge of the second stopper protrusion 124 can be brought into contact with the inner side wall of the outer fixing member 11, and the inner edge of the third stopper protrusion 112 can be brought into contact with the outer side wall of the inner fixing member 12, thereby improving the sealing performance of the spark plug.

Alternatively, the second and third position-defining

projections

124 and 112 may have the same projection height, and both are greater than (D1-D2)/4 and less than (D1-D2)/2.

In this way, the second stopper protrusion 124 and the third stopper protrusion 112 overlap in a direction perpendicular to the first end surface 121A, and the outer fixing member 11 can be prevented from falling off from the first end 122 of the inner fixing member 12.

Meanwhile, the outer side edge of the second stopper protrusion 124 may not contact the inner side wall of the outer fixing member 11, and the inner side edge of the third stopper protrusion 112 may not contact the outer side wall of the inner fixing member 12. On one hand, the outer fixing member 11 and the inner fixing member 12 are not in contact, so that the resistance of the rotation of the outer fixing member 11 is reduced, and the mounting efficiency of the spark plug is improved. On the other hand, since the spark plug needs to frequently rotate the outer fixing member 11 when it is installed, if the outer fixing member 11 contacts the inner fixing member 12, the contact position may be damaged due to friction, and thus the protrusion heights of the second and third limiting

protrusions

124 and 112 are set to the above-mentioned dimensions, it is possible to prevent the outer fixing member 11 from contacting the inner fixing member 12, and further, the service life of the fixing member 1 is prolonged.

In practice, the outer fixing member 11 without the third position-limiting protrusion 112 may be first sleeved outside the inner fixing member 12 through the first end 122 of the inner fixing member 12, and then the third position-limiting protrusion 112 may be clamped by a jig at a position between the second position-limiting protrusion 124 and the external thread 111.

The third structural feature is that one end of the external fixing member 11 away from the first limiting protrusion 121 may have a bolt cap structure 113.

As shown in fig. 5, one end of the external fixing member 11 away from the first limiting protrusion 121 is a bolt cap structure 113, wherein the bolt cap structure may be a 6-angle bolt cap structure, or a 12-angle bolt cap structure.

Thus, a technician can use a wrench of a type corresponding to the bolt cap structure 113 to rotate the outer mount 11 about the axis of the outer mount 11, and screw the outer mount 11 into the engine cylinder head through the external threads 111, thereby improving the efficiency of installing the spark plug.

The structure is characterized in that the rotation limiting chuck 52 can be of a solid structure or a hollow structure.

Alternatively, as shown in fig. 6, the rotation limit clip 52 may have a hollow structure.

Thus, the processing difficulty of the hollow-structure rotation limiting chuck 52 in the process of manufacturing the clamping groove 52A is small, and the processing efficiency of the clamping groove 52A can be improved.

Alternatively, the rotation limit clip 52 may have a solid structure.

Thus, since the catching groove 52A requires a catching tool for restricting the rotation of the terminal rod 5 during the installation of the spark plug. The solid structure of the rotation limiting chuck 52 can provide greater strength, and the overall strength of the spark plug is improved.

The structure is characterized in that the clamping groove 52A of the rotation limiting clamping head 52 can be a through groove.

As shown in fig. 6, the engaging groove 52A penetrates from one side to the other side of the rotation limiting chuck 52.

Like this, when with fixing tool joint in draw-in groove 52A, can be with the fixing tool joint in the both sides of rotatory spacing dop 52, compare in only in one side joint fixing tool, the torsional stress that can disperse draw-in groove 52A received to improve draw-in groove 52A's intensity.

Alternatively, the penetrating direction of the card slot 52A and the orientation of the side electrode 6 may be the same. The orientation of the side electrode 6 is the direction from the side electrode 6 to the center electrode 3.

As shown in fig. 7, the direction from the side electrode 6 to the center electrode 3 is the same as the penetrating direction of the card slot 52A.

Thus, when the spark plug is mounted, the side electrode is positioned inside the cylinder head of the engine, and the direction of the side electrode cannot be directly known to a technician. Therefore, the direction of penetration of the card slot 52A and the direction of the side electrode 6 are set to the same direction, and the technician can determine the direction of the side electrode 6 from the direction of penetration of the card slot 52A. If the penetrating direction of the clamping groove 52A is changed during installation of the spark plug, which indicates that the orientation of the side electrode 6 is also changed, a technician can adjust the penetrating direction of the clamping groove 52A to a specified direction, so as to ensure that the orientation of the side electrode 6 is in the specified direction.

The structure is characterized in that the inner fixing piece 12 and the ceramic body 2 can be connected in a sealing way. The sealing connection may be achieved by arranging talc powder or an inner gasket between the inner fixing member 12 and the ceramic body 2, wherein the inner gasket may be made of various materials with good heat resistance, such as nickel-iron alloy.

Since the inner fixing member 12 and the ceramic body 2 are fixedly connected by riveting or the like, there may be a gap between the inner fixing member 12 and the ceramic body 2, through which the mixed gas in the cylinder head of the engine may escape to the outside of the spark plug, resulting in occurrence of a safety accident. The talcum powder or the inner gasket is arranged between the inner fixing piece 12 and the ceramic body 2, so that the mixed gas in the cylinder cover of the engine can be effectively prevented from overflowing out of the spark plug, and the safety of the spark plug is improved.

With the spark plug of the present application, since the spark plug includes the fixing member, the ceramic body, the terminal rod, and the side electrode. The fixing piece comprises an outer fixing piece and an inner fixing piece, the outer fixing piece is rotatably connected with the inner fixing piece, the outer fixing piece is provided with external threads and can be in threaded connection with the engine cylinder cover, a first limiting protrusion is arranged on the outer side wall of the inner fixing piece, and the first end face of the first limiting protrusion is in contact with the outer fixing piece. The rotation limiting chuck of the junction pole is provided with a clamping groove. The side electrodes are connected to the inner fixing member, and the junction rod and the inner fixing member are connected to the ceramic body. The rotation limiting chuck can rotate synchronously with the side electrode. Like this, when the installation spark plug, can get up the draw-in groove joint of fixing tool and spacing dop, when keeping fixing tool to be in irrotational state, rotatory outer mounting is fixed with outer mounting and engine cylinder head. The fixed of holding fixing tool can keep rotatory spacing dop irrotational to guarantee that the orientation of side electrode does not take place rotatoryly, can be towards the direction that is favorable to the engine to strike sparks most, improve the engine success rate of striking sparks.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A spark plug, characterized in that it comprises a fixing member (1), a ceramic body (2), a center electrode (3), a resistance seal (4), a terminal rod (5) and side electrodes (6);

the fixing piece (1) comprises an outer fixing piece (11) and an inner fixing piece (12), the outer fixing piece (11) is of a tubular structure and is provided with an external thread (111), the external thread (111) is used for being connected with an engine cylinder cover, the inner fixing piece (12) is of a tubular structure, a first limiting bulge (121) is arranged on the outer side wall of the inner fixing piece (12), the part, between a first end (122) and the first limiting bulge (121), of the inner fixing piece (12) is located in the outer fixing piece (11) and is in rotating connection with the outer fixing piece (11), the part, between a second end (123) and the first limiting bulge (121), of the inner fixing piece (12) is located outside the outer fixing piece (11), and the first limiting bulge (121) is provided with a first end face (121A), a second end face (121B) and a first side face (121C), the first end face (121A) is in contact with the outer fixing piece (11), the second end face (121B) is used for being in contact with the engine cylinder head, and the diameter of the first side face (121C) is smaller than the small diameter of the external thread (111);

the ceramic body (2) is of a tubular structure, and the ceramic body (2) is positioned in the inner fixing piece (12) and connected with the inner fixing piece (12);

the central electrode (3) is positioned in the ceramic body (2), one end of the central electrode (3) extends out of one end of the ceramic body (2) and the second end (123) of the inner fixing piece (12), and the central electrode (3) is connected with the ceramic body (2);

the resistor sealing material (4) is positioned in the ceramic body (2) and connected with the ceramic body (2), and one end of the resistor sealing material (4) is connected with the other end of the central electrode (3);

the wiring rod (5) comprises a rod body (51) and a rotary limiting chuck (52), the rod body (51) is located in the ceramic body (2) and connected with the ceramic body (2), and one end of the rod body (51) is connected with the other end of the resistance sealing material (4); the rotation limiting clamping head (52) is located at the other end of the ceramic body (2) and connected with the ceramic body (2) and the rod body (51), a clamping groove (52A) is formed in one end, away from the ceramic body (2), of the rotation limiting clamping head (52), and the clamping groove (52A) is used for being clamped with a fixing tool to prevent components, except the outer fixing piece (11), in the spark plug from rotating relative to the outer fixing piece (11);

the side electrode (6) is located at the second end (123) of the inner fixing member (12) and is connected with the inner fixing member (12).

2. The spark plug as claimed in claim 1, wherein a first end surface (121A) of the first stopper protrusion (121) is a circular ring surface and is perpendicular to an outer side wall of the inner fixing member (12), a second end surface (121B) of the first stopper protrusion (121) is a conical surface, and a radius of the conical surface at a position close to the first end surface (121A) is larger than a radius of the conical surface at a position away from the first end surface (121A).

3. The spark plug of claim 2 further including a stop washer (7), said stop washer (7) being located on said second end face (121B) and being connected to said second end face (121B).

4. A spark plug according to claim 3, characterized in that the stop washer (7) is made of an elastic non-slip material.

5. The spark plug of claim 1, wherein the outer side wall of the inner fixing member (12) further has a second stopper protrusion (124), the second stopper protrusion (124) being located between the first stopper protrusion (121) and the first end (122) of the inner fixing member (12); the inner wall of the outer fixing piece (11) is provided with a third limiting protrusion (112), the third limiting protrusion (112) is located between the first limiting protrusion (121) and the second limiting protrusion (124), and the inner diameter of the third limiting protrusion (112) is smaller than the outer diameter of the second limiting protrusion (124).

6. The spark plug as claimed in claim 1, wherein an end of the outer fixing member (11) remote from the first stopper protrusion (121) has a bolt cap structure (113).

7. The spark plug as recited in claim 1, wherein the rotation limit clip (52) has a solid or hollow structure.

8. The spark plug according to claim 1, wherein the engaging groove (52A) of the rotation-limiting chuck (52) is a through-type groove.

9. The spark plug according to claim 8, wherein the direction of penetration of the slot (52A) and the orientation of the side electrode (6) are the same.

10. The spark plug as claimed in any one of claims 1 to 9, wherein the inner fixing member (12) is sealingly connected to the ceramic body (2).